Whenever you hear about a serial killer on the loose, you probably think in terms of someone who is an absolute madman. A Charles Manson, John Wayne Gacy, etc. Not necessarily someone who could be committing a series of ... hate crimes. But that could very well be what's going on in Brooklyn, where three storekeepers -- all of Middle Eastern descent -- have been shot dead in the last five months. Horrifying.

The most recent death was that of 78-year-old Rahmatollah Vahidipour, a Jewish man from Iran who was shot in his women's clothing boutique in Brooklyn, late on Friday of last week. The other victims -- Mohamed Gebeli, an Egyptian immigrant and a Muslim, and IsaacKadare, also Egyptian but Jewish -- were shot on July 6 and August 2 respectively. Police have linked all three murders to the same .22-caliber gun.

It sounds like hate crime is not at all out of the question, but there's another bizarro aspect here: New York newspapers have been noting that the killer appears to be obsessed with the number eight, which "features in all three murder scene addresses." Huh ... Not so sure that has anything to necessarily do with the killer's motive, though, right?

As for that, there's always the chance that we're just overthinking this, and the storekeepers' backgrounds may really just be an unnerving coincidence. That's because police say robbery hasn't yet been excluded as the killer's main motive ...

But to think that these murders could have been hate crimes really does take the concern to a whole different, worrisome level. Thankfully, detectives who specialize in hate crimes and FBI analysts who specialize in behavioral analysis have joined the case, according to authorities. So one way or the other, regardless of his motives, let's hope the killer is found and taken off the streets ASAP.